The invention relates to a sensor module in which a position sensor is connected to an electronic evaluation unit which conditions the signal output by the position sensor and corresponding to the position of a component to be monitored.
In known sensors, the signal output by the sensor is fed to an electronic evaluation unit which conditions the sensor signal for further processing by a connected electronic system. Thus, for example, the signal of a position sensor arranged in a motor vehicle, which represents a variation in the position of a component to be monitored such as the throttle valve, is relayed to an electronic engine management system which generates a control signal for driving the internal combustion engine on the basis of the sensor signal.
In the electronic evaluation unit, the sensor signal is amplified and an output signal is generated which is corrected in terms of the zero point and/or temperature.
When the sensor and the electronic evaluation unit are being installed, the two must be tuned to one another. After a preliminary adjustment at the respective manufacturer, the two individual parts must be tuned to one another yet again when being installed in the apparatus which contains the component whose position is to be monitored. Such an adjustment is very complicated. The spatial separation of sensor and electronic evaluation unit requires an additional outlay on wiring.
It is therefore the object of the invention to specify a sensor arrangement which can be produced simply and with a reduced outlay on adjustment.
According to the invention, the object is achieved by virtue of the fact that the position sensor and the electronic evaluation unit are jointly arranged at or on a shape sheet-metal part, the shaped sheet-metal part being designed as a conductor track structure, at least between the sensor and an electronic evaluation unit for the purpose of an electric connection, which conductor track structure is angled off to adapt to the installation site of the sensor.
The advantage of the invention consists in that accurate placement of the sensor on the component to be monitored is possible owing to the arrangement on a shaped sheet-metal part. It is possible to dispense with connecting lines between the sensor and electronic evaluation unit, thereby reducing the size of the design of the module. The sensor and electronic evaluaton unit are adjusted jointly in one step. Not only can a position sensor module thus created be programmed simply in offset and measuring range, but it can also be used for diagnostic purposes such as, for example, to determine a line breakage or short circuit between the sensor and electronic evaluation unit.
In a preferred embodiment, the sensor is designed as a magnetoresistive sensor which is arranged in a magnetic field.
The sensor is advantageously arranged approximately at the center of a cylindrically designed permanent magnet. An accurate placement of the sensor in the homogeneous part of the magnetic field is possible owing to the angling-off of the shaped sheet-metal part.
In an advantageous refinement, the sensor is positioned at a first outer end of the shaped sheet-metal part, the end of the shaped sheet-metal part which projects beyond the electronic evaluation unit in the opposite direction to the sensor being formed by at least one freely ending conductor track of the shaped sheet-metal part. A simple electric connection of the shaped sheet-metal part to other electric circuits is possible in this way.
In a development of the invention, the free end of the shaped sheet-metal part is electrically connected to a second shaped sheet-metal part, which supports passive electric components and on which the contact device is formed. Because of the use of shaped sheet-metal parts, components required for particular applications can be arranged thereon and connected to one another electrically via the shaped sheet-metal part, and thereby form a compact device which is mounted in vibration-free fashion, particularly for use in motor vehicles. Contact may be made between the two shaped sheet-metal parts with the aid of conventional joining techniques such as welding or soldering.
The contact device or the free end of the conductor track itself can advantageously be constructed as a plug-in device, it thereby being possible to dispense with the fastening of a separate plug.
The sensor and the electronic evaluation unit are separately housed in order to protect the sensor and the electronic evaluation unit during installation at the installation site, for example in a motor vehicle.
In order to produce a position sensor module supplying redundant output signals, a first and a second identically constructed sensor unit respectively consisting of a sensor, a shaped sheet-metal part and an electronic evaluation unit are present, the shaped sheet-metal part of each sensor unit being bent by approximately 90 degrees between the sensor and electronic evaluation unit, and the two sensor units being inserted into the cylindrically designed magnet such that the sensors are arranged lying immediately one above another, while the electronic evaluation units of the two sensor units are arranged decentrally in each case, lying opposite one another, outside the sensor dimensions.